Watonwan River - Geography

Geography

The Watonwan River rises in Amboy Township, approximately three miles (5 km) southwest of Jeffers in central Cottonwood County, and flows generally eastwardly across flat till plains through northern Watonwan and western Blue Earth Counties, past the city of Madelia. It flows into the Blue Earth River approximately eight miles (13 km) southwest of Mankato and 16 miles (26 km) upstream of the Blue Earth's confluence with the Minnesota River.

The river's largest tributaries are its north and south forks. The South Fork Watonwan River, 73 miles (118 km) long, rises in southeastern Cottonwood County and initially flows eastwardly into southern Watonwan County, briefly entering Martin County and passing Odin; then northeastwardly through eastern Watonwan County to its confluence with the Watonwan River upstream of Madelia. The North Fork Watonwan River, 39 miles (63 km) long, rises in Cottonwood County and flows eastwardly into northern Watonwan County, joining the Watonwan River about a mile (2 km) southeast of La Salle.

Approximately 84% of the larger watershed of the Blue Earth River, which includes that of the Watonwan River, is used for agricultural cultivation, primarily that of corn and soybeans. Small lakes and wetlands in the Watonwan watershed provide significant habitat for Minnesota's waterfowl population, though many stretches of the river and its tributaries have been subject to ditching and channelization for agricultural production and localized flood reduction.